A fuel cell vehicle includes a fuel cell stack in which a plurality of fuel cells used as a power source are stacked and a fuel supplier supplying hydrogen or the like, which is fuel, to the fuel cell stack. An air supplier supplies oxygen which is an oxidizing agent necessary for an electrochemical reaction. Water and heat manager controls a temperature of the fuel cell stack.
The fuel supplier depressurizes compressed hydrogen in a hydrogen tank and supplies it to an anode of the stack, and the air supplier supplies external air inhaled by actuating an air blower to a cathode of the stack.
When hydrogen is supplied to the anode, and oxygen is supplied to the cathode, hydrogen ions are separated from the anode by a catalyst reaction. The separated hydrogen ions are transferred to the cathode which is an air electrode through an electrolyte membrane. The hydrogen ions separated from the anode, electrons, and oxygen are electrochemically reacted together at the cathode, thereby generating electrical energy. Specifically, electrochemical oxidation of hydrogen is generated from the anode, and electrochemical reduction of oxygen is generated from the cathode. Due to the movement of electrons generated in this case, electricity and heat are generated, and due to the chemical operation in which hydrogen and oxygen are bonded, vapor or water is generated.
A discharging apparatus is provided for discharging by-products, such as vapor, water, and heat generated during a process of generating the electrical energy of the fuel cell stack, and un-reacted hydrogen, oxygen, and the like, and gases such as vapor, hydrogen, and oxygen are discharged to the atmosphere through an exhaust passage.
An air blower, a hydrogen recycle blower, a water pump, and the like for driving the fuel cell are connected to a main bus terminal to facilitate a start of the fuel cell. The main bus terminal may be connected to various relays for facilitating power blocking and connection and a diode preventing a flow of a reverse current into the fuel cell.
Dry air supplied through the air blower is humidified by a humidifier and then supplied to the cathode of the fuel cell stack. An exhaust gas of the cathode may be transferred to the humidifier in a humidified state by water component generated therein to humidify the dry air to be supplied to the cathode.
At the time of tip-out or deceleration of the fuel cell vehicle, a driving motor becomes a low load/no load state or a regenerative braking state, thereby using a little driving current or no driving current. Due to a slow response speed of the air blower, the driving motor is in a temporarily infinite air supercharging state, such that the fuel cell stack may dry out.